1. FIELD OF THE INVENTION
This invention relates to the fluidized catalytic cracking (FCC) conversion of heavy hydrocarbons into lighter hydrocarbons with a fluidized stream of catalyst particles and regeneration of the catalyst particles to remove coke which acts to deactivate the catalyst. More specifically, this invention relates to the routes of catalyst transfer and feed and catalyst contacting.
2. DESCRIPTION OF THE PRIOR ART
Catalytic cracking is accomplished by contacting hydrocarbons in a reaction zone with a catalyst composed of finely divided particulate material. As the cracking reaction proceeds, substantial amounts of coke are deposited on the catalyst. A high temperature regeneration within a regeneration zone operation burns coke from the catalyst. Coke-containing catalyst, referred to herein as spent catalyst, is continually removed from the reaction zone and replaced by essentially coke-free catalyst from the regeneration zone. Fluidization of the catalyst particles by various gaseous streams allows the transport of catalyst between the reaction zone and regeneration zone. Methods for cracking hydrocarbons in a fluidized stream of catalyst, transporting catalyst between reaction and regeneration zones, and combusting coke in the regenerator are well known by those skilled in the art of FCC processes. To this end, the art is replete with vessel configurations for contacting catalyst particles with feed and regeneration gas, respectively.
Despite the long existence of the FCC process, techniques are continually sought for improving product recovery both in terms of product quantity and composition, i.e. yield and selectivity and for improving process operation. Improving process operation typically means the removal or simplification of equipment. Two operational functions that can improve product yield are initial feed and catalyst contacting and separation of converted feed components from catalyst. Improvement in the separation of hydrocarbons from spent catalyst and initial feed and catalyst contacting tends to benefits yield and selectivity.
It is an object of this invention to improve FCC arrangements that eliminate the large reaction and regeneration vessels.
It is a further object of this invention to improve feed and catalyst contacting and product and catalyst separation.
A yet further object of this invention is the to simplify the equipment arrangement for the stripping and separation of cracked hydrocarbons from spent catalyst.